Classify oversized tool results safely

[first-assist]

Summary

• preserve oversized tool-result failures as a typed runtime error
• classify that error as a retryable, content-free application-tool failure
• distinguish descriptor and transport result-budget failures from opaque execution failures
• release the affected profile and runtime crates with migration notes

Safety properties

• does not weaken descriptor byte or record ceilings
• does not disclose rejected response content
• leaves authentication, authorization, disclosure-schema, and malformed-result failures unchanged
• preserves compatibility defaults for existing executors

Documentation impact

• Documentation updated
• No documentation impact

Verification

• focused runtime contracts, including transport and descriptor byte limits
• full tool-profile and AI runtime suites
• Codex app-server provider suite
• warnings-denied Clippy for aggregate providers and Codex app-server
• warnings-denied Rustdoc for both changed crates and provider configurations
• documentation, inventory, release-state, release-manifest, dependency, package-policy, and SemVer gates
• formatting, diff checks, and restricted-vocabulary scans